1. Field of the Invention
This invention relates to peeling rollers used for peeling and stripping epidermises of root crops or other elongate vegetables such as carrots, radishes, burdocks, etc. at high speed and smoothly. More particularly, this invention is concerned with a pair of peeling rollers for use in a peeling apparatus of a type in which the peeling rollers are disposed in parallel with each other and driven to revolve in mutually opposite directions and, when an objective material to be treated is inserted between them, serve to abrade or scrape the epidermis of it as well as soil and mire attached.
2. Statement of Related Art
In the peeling work of various elongate vegetables whose edible parts are grown in the soil, manual work of a worker has been conducted with the aid of a knife or any simple peeling tool, after removal of the soil and mud therefrom. Particularly where they are treated in large quantities, such manual work not only has caused deterioration of the working environment, contamination to the worker him- or herself, and fatigue and exhaustion at his or her various body parts which may eventually affect adversely on the health, but also has had a tendency of peeling epidermises of the vegetables toward being stripped too much or being stripped unevenly, which has led to reduction in efficiency and yield.
In order to eliminate the drawbacks of peeling treatment by manual work, various peeling machines are provided and known, for example, one comprising a pair of rollers equipped with brushes on their surfaces. With this peeling machine, however, as a peeling work progresses, soil and mire attached to an objective material enter the brushes to accumulate therein and peeling dusts also accumulate in the brushes while the brushes are worn off, impaired and deformed, with the result that the peeling work becomes substantially inoperable or peeling efficiency is significantly decreased.
The present inventor has already proposed several peeling devices equipped with cylindrical rollers based on peeling action of abrasion or scraping, in view of the defects in the existing peeling machines. The peeling rollers are each formed of an hourglass-shaped roller core, an outer elastomer member surrounding concentrically the core which member is attached thereon with granulate abrasive pieces, the elastomer member consisting of a plurality of plate-like pieces, and a damper of elastomer foam filling the space enclosed by a recessed portion of the core and the elastomer member, whereby elasticity or pliability of the elastomer member and the damper induced by centrifugal force upon high speed revolution and abrasion action of the abrasive material are exploited.
These solid type peeling devices are operated so that by the revolution of the hourglass-shaped core rollers, the elastomer members attached with the abrasive pieces press against and abrade the surface of a material to be treated, and consequently, have the advantages that the treating time is substantially shortened as compared with conventional peeling devices and homogeneous peeling over the whole surface of the treating material is possible. When the peeling rollers are revolved at high speed, however, a problem frequently occurs owing to the fact that the foam gradually absorbs water rather than functioning as a damper. That is, because of the absorption of water in the foam, the rollers distend in their central areas to assume a barrel form, as a result of which, in an extreme case, the rollers come into contact with each other in their outer circumferences of the central areas owing to the centrifugal force and the abrasive granules are detached to scatter, causing ultimately even breakdown of the rollers. Even in a non-extreme case, it is not possible to treat the surface of the material homogeneously and the surface areas of the peeling rollers which can partake of the treatment are decreased, which runs into the reduction in peeling efficiency. Thus, they have yet remained to be improved.
The inventor has investigated further into the foregoing problems to avoid the phenomenon that the rollers are distended in barrel form upon revolution, and found that the problems can be solved unexpectedly by constituting the space enclosed between the outer elastomer member of cylindrical body and the recessed portion of the core roller as a hollow.